论文部分内容阅读
用MMS-200热力模拟试验机研究了低合金耐磨钢NM400在连续冷却条件下的组织演变规律,测定了不同化学成分钢的静态CCT曲线和动态CCT曲线,分析了变形及合金元素对组织转变的影响。结果表明:奥氏体区的变形促进铁素体相变,贝氏体相变温度降低,形成马氏体临界冷却速率提高。Mo抑制碳的扩散,细化晶粒,Ni的添加更加降低马氏体的临界冷却速率。冷速在10℃/s以上时,硬度超过400 HV,传统离线淬火及轧后在线超快冷工艺生产NM400钢均具有可行性。
The microstructure evolution of the low alloyed wear-resistant steel NM400 under continuous cooling was investigated by MMS-200 thermal simulation test machine. The static CCT curves and dynamic CCT curves of different chemical compositions were measured. The effects of deformation and alloying elements on the microstructural transformation Impact. The results show that the deformation of austenite region promotes the ferrite transformation and the bainite transformation temperature decreases, and the critical cooling rate of martensite formation increases. Mo inhibits the diffusion of carbon, grain refinement, and the addition of Ni further reduces the critical cooling rate of martensite. When the cooling rate is above 10 ℃ / s, the hardness exceeds 400 HV, and it is feasible to produce NM400 steel by traditional off-line quenching and on-line ultra-rapid cooling after rolling.